Hepatic artery thrombosis in living related liver transplantation

BACKGROUND: Hepatic artery thrombosis (HAT) after orthotopic liver transplantation remains a significant cause of graft loss in pediatric patients. We previously reported that the microsurgical techniques for arterial anastomosis can reduce the incidence of HAT in living related liver transplantation (LRLT). The purpose of this study is to analyze the risk factors for HAT after LRLT. A total of 245 patients received 250 liver transplants. METHODS: Eight arteries in eight patients, reconstructed with the use of loupe magnification (HAT; 1/8, 12.5%), were excluded from this study. We observed HAT in 4 patients of the 242 transplants (1.7%, HAT group). Seventeen factors were compared between the HAT and the control group (those without HAT). RESULTS: HAT occurred in 3 of 33 grafts (9%) from ABO-incompatible donors, whereas it occurred in 1 of 209 grafts (0.5%) from identical or compatible donors (P=0.008). The corrected volume of fresh-frozen plasma intraoperatively transfused in the HAT group (46.9+/-30.3 ml/kg) was significantly (P=0.015) different from that in the control group (10.2+/-1.9 ml/mg). In all four patients with HAT, emergent revisions of the anastomosis were performed. Two patients with ABO-incompatible grafts died of hepatic failure and sepsis. CONCLUSIONS: Although microsurgical techniques can minimize the surgical risk factors for HAT, overtransfusion of fresh-frozen plasma in high-risk patients (ABO incompatible) may be a critical factor in the development of HAT in LRLT.     

Impact of N-acetylcysteine on the hepatic microcirculation after orthotopic liver transplantation

Recent observations showed an improvement of hepatic macro- and microhemodynamics as well as survival rates after warm ischemia of the liver following treatment with N-acetylcysteine (NAC). In this study we assessed the influence of NAC on the hepatic microcirculation after orthotopic liver transplantation (OLT) using intravital fluorescence microscopy. OLT with simultaneous arterialization was performed in 16 male Lewis rats following cold storage in University of Wisconsin solution for 24 hr. Within the experimental group (n = 8) donors received NAC (400 mg/kg) 25 min before hepatectomy. In addition, high-dose treatment of recipients with NAC (400 mg/kg) was started with reperfusion. Control animals (n = 8) received an equivalent amount of Ringer's solution. Intravital fluorescence microscopy was performed 30-90 min after reperfusion assessing acinar and sinusoidal perfusion, leukocyte-endothelium interaction, and phagocytic activity. Treatment with NAC reduced the number of nonperfused sinusoid from 52.4 +/- 0.8% to 15.7 +/- 0.5% (p = 0.0001) (mean +/- SEM). Furthermore, we achieved a significant reduction of leukocytes adhering to sinusoidal endothelium (per mm2 liver surface) from 351.9 +/- 13.0 in controls to 83.6 +/- 4.2 in the experimental group (P = 0.0001). In postsinusoidal venules, treatment with NAC decreased the number of sticking leukocytes (per mm2 endothelium) from 1098.5 +/- 59.6 to 425.9 +/- 37.7 (P = 0.0001). Moreover, bile flow was significantly increased after therapy with NAC (4.3 +/- 1.2 vs. 2.2 +/- 0.7 ml/90 min x 100g liver) (P < 0.05). Phagocytic activity was not influenced by application of NAC. We conclude that high-dose therapy with NAC in OLT attenuates manifestations of microvascular perfusion failure early after reperfusion and should be considered as a means to reduce reperfusion injury.     

Infected false hepatic artery aneurysm after orthotopic liver transplantation treated by resection and reno-hepatic vein graft

Marked gastric distention was-observed in rats 20 h after they underwent partial hepatectomy under isoflurane anesthesia and received buprenorphine (0.3 mg/kg of body weight) after surgery. Hardwood bedding comprised the bulk of the gastric contents. A study was undertaken to determine the cause of the pica behavior (consumption of non-nutritive substances) and resultant gastric distention. Ten-week-old male Sprague Dawley rats were randomly assigned to one of six groups. Group-1 rats (n = 11) underwent laparotomy under isoflurane anesthesia, with buprenorphine (0.3 mg/kg) administered after surgery. Group-2 rats (n = 12) underwent laparotomy under isoflurane anesthesia with buprenorphine (0.05 mg/kg) administered after surgery. Group-3 rats (n = 24) underwent laparotomy under isoflurane anesthesia, with saline administered after surgery. Isoflurane was administered at the same rate, concentration, and duration for all groups that underwent laparotomy (groups 1 to 3). Buprenorphine or saline was administered subcutaneously as a single injection when anesthesia was discontinued (groups 1 to 3). Group-4 rats (n = 6) received buprenorphine (0.3 mg/kg) only. Group-5 rats (n = 6) received buprenorphine (0.05 mg/kg) only. Group-6 rats (n = 12) received saline only. Rats not undergoing laparotomy (groups 4 to 6) received buprenorphine or saline 18 to 20 h before euthanasia. Rats were housed individually in filter-topped polycarbonate cages containing hardwood bedding. A purified, pelleted diet and water were offered ad libitum. Food and water consumption were measured over the posttreatment period. Eighteen to 20 h after treatment, rats were euthanized, each stomach and its contents were weighed, contents were examined grossly, and wet and dry gastric content weights were recorded. All weights were significantly (P < 0.05) increased in rats receiving buprenorphine administered after surgery (groups 1 and 2), compared with rats of the control group (group 3). Weights of the stomach and contents, wet gastric contents, and dry gastric contents were significantly (P < 0.05) increased in rats receiving 0.3 mg of buprenorphine/kg only (group 4), compared with values for their controls (group 6). Hardwood bedding comprised the bulk of the gastric contents in all groups receiving buprenorphine. Stomachs of rats not receiving buprenorphine contained the purified diet with little or no hardwood bedding. These results indicate that a single injection of buprenorphine at a dosage of 0.05 or 0.3 mg/kg resulted in rats ingesting hardwood bedding, leading to gastric distention. It was concluded that pica behavior associated with administration of buprenorphine should be considered when evaluating experimental data from rats housed on contact bedding.     

Epstein-Barr virus-related localized hepatic lymphoproliferative disorders after liver transplantation

BACKGROUND: Localized hepatic post-transplant lymphoproliferative disease is uncommon. In such cases, lymphocyte Epstein-Barr virus (EBV) infection may promote an intrahepatic B-lymphocyte monoclonal expansion. METHODS: From 1990 to 1991, 149 patients underwent liver transplantation for various liver failures. Immunosuppressive therapy was azathioprine, cyclosporine-A, and methylprednisolone. Rejection episodes were treated by methylprednisolone bolus injection with or without OKT3 therapy. Three patients (2%), aged 38, 50, and 47 years, developed lymphoproliferative disease localized in the transplanted livers within 5 months of liver transplantation (a patient had been immunosuppressed for 3 years before the lymphoproliferative disease occurred within the third allografted liver). Diagnoses were obtained by fine needle aspiration. In situ hybridizations were performed with the kappa/lambda mRNA-kit FITC DAKO (DAKO Corporation, Carpenteria, CA) and the early mRNA-EBER oligonucleotide FITC DAKO: RESULTS: Lymphoproliferative diseases were all classified as diffuse polymorphic large cell lymphomas in the working formulation and considered as lymphoproliferative disorders with polymorphic large cells in the Frizzera classification. All large cells were CD20-positive, CD45-positive and CD45RO-negative. In situ mRNA light chain hybridization demonstrated monoclonality in two cases. In all three cases, EBV mRNA was detected in large cells by early mRNA-EBV (EBER) in situ hybridization. Patients were treated with doxorubicin, cyclophosphamide, vincristine, and VM26. Two patients maintained a complete remission 3 years after six cycles of chemotherapy, whereas one died of an early opportunistic infection. CONCLUSION: Epstein-Barr virus may play a special role in the pathogenesis of lymphoproliferative disorders that develop in patients who have undergone liver transplantation.     

Long-term results after liver transplantation for primary hepatic epithelioid hemangioendothelioma

BACKGROUND: Hepatic epithelioid hemangioendothelioma (PHEHE) is a multifocal, low-grade malignant neoplasia characterized by its epithelial-like appearance and vascular endothelial histogenesis. The outcome of 16 patients treated with orthotopic liver transplantation (OLT) is the subject of this report. METHODS: A retrospective study of 16 patients with HEHE (7 men, 9 women) with ages ranging from 24 to 58 years (mean 37 +/- 10.6 years). Follow-up intervals ranged from 1 to 15 years (median of 4.5 years). RESULTS: Actual patient survival at 1, 3, and 5 years was 100, 87.5, and 71.3%, respectively. Disease-free survival at 1, 3, and 5 years was 81.3, 68.8, and 60.2%, respectively. The 90-day operative mortality was 0. Involvement of the hilar lymph nodes or vascular invasion did not affect survival. The 5-year survival of HEHE compares favorably with that of hepatocellular carcinoma at the same stage (stage 4A): 71.3 versus 9.8% (p = 0.001) CONCLUSIONS: The long-term survival obtained in this series justifies OLT for these tumors even in the presence of limited extrahepatic disease.     

Neutrophil and macrophage activation and anaphylatoxin formation in orthotopic liver transplantation without the use of veno-venous bypass

BACKGROUND: Activation of neutrophils and activation of complement may be an aetiologic factor behind circulatory insufficiency in association with reperfusion of the grafted liver. METHODS: Neutrophil and macrophage activation (determined as PMN elastase and neopterin release) and complement activation were evaluated in 15 consecutive patients undergoing orthotopic liver transplantation without the use of veno-venous bypass. RESULTS: The PMN elastase concentrations were increased at the end of the anhepatic phase, 2, 5 and 30 min after start of reperfusion and 6 and 24 h postoperatively. There were significantly higher PMN elastase concentrations in patients with circulatory instability (postreperfusion syndrome) compared with those without postreperfusion syndrome. The neopterin concentration was increased 2 min after the start of reperfusion and remained elevated until 6 h postoperatively. The plasma complement C3a concentrations were increased at the end of the anhepatic phase and 2, 5 and 30 min after the start of reperfusion. The plasma C3a levels were higher in patients with postreperfusion syndrome compared to those without. CONCLUSIONS: Activation of neutrophils and macrophages and of the complement cascade with the formation of biologically active substances may be one explanation for the circulatory instability often seen in patients undergoing orthotopic liver transplantation.     

Intraoperative placement of a Wallstent for portal vein stenosis and thrombosis after liver transplantation

We report a case of orthotopic liver transplantation, in which portal vein thrombosis developed in the immediate postoperative period. Surgical thrombectomy and intraoperative placement of a large caliber Wallstent resulted in long-term patency. The unique feature of this case is the intraoperative placement of the stent via the inferior mesenteric vein under fluoroscopic guidance. The use of a large caliber (16 mm) stent obviated the need for postoperative anticoagulation.     

Role of glutathione in hepatic bile formation during reperfusion after cold ischemia of the rat liver

BACKGROUND/AIMS: Liver reperfusion following cold ischemia is frequently associated with diminished bile flow in patients undergoing liver transplantation. Glutathione is a major determinant of bile-acid independent bile flow, and the effects of cold ischemia on biliary glutathione excretion are unknown. METHODS: We examined the effects of cold ischemia (University of Wisconsin solution (4 degrees C), 24 h) with subsequent reperfusion (100 min) on biliary glutathione excretion in a recirculating system. Since glutathione might represent an important antioxidant within the biliary tract and oxidative stress in the biliary tract during reperfusion could contribute to the pathogenesis of bile duct injury after liver transplantation, we also assessed bile duct morphology in reperfused livers of mutant TR- -rats, in whom biliary excretion of glutathione is already impaired. RESULTS: Hepatic bile formation was diminished in reperfused Wistar rat livers after cold ischemia. Biliary glutathione concentrations and output were significantly decreased and correlated with postischemic changes in bile secretion. An increased biliary oxidized glutathione/glutathione ratio, indicating oxidative stress, was detected only immediately after the onset of reperfusion. Basal bile flow rates in TR- -rat livers which were already markedly reduced in control-perfused livers, decreased further during the early but not the later reperfusion period. Reperfusion of both Wistar and TR- -rat livers was not associated with electron microscopic evidence of bile duct damage. CONCLUSIONS: We conclude that impaired biliary excretion of glutathione contributes to decreased bile flow after cold ischemia. The absence of biliary glutathione does not appear to promote ultrastructural evidence of bile duct injury during reperfusion in the isolated perfused rat liver.     

Predictive value of von Willebrand factor to ristocetin cofactor ratio and thrombin-antithrombin complex levels for hepatic vessel thrombosis and graft rejection after liver transplantation

Acute cellular rejection and hepatic vessel thrombosis are significant postoperative complications of liver transplantation. The study investigated changes in endothelial cell-related hemostatic proteins in the peripheral circulation of patients after liver transplantation, and assays for hemostatic parameters were compared with data from routine hematologic and biochemical investigations, together with clinical information. Of the 12 patients, 8 underwent acute rejection episodes. No significant differences in any hemostatic parameter measured were seen between rejection and nonrejection groups, with the exception of the platelet count, which increased after treatment of the rejection episode. Two of the 12 patients suffered fatal hepatic vessel thrombosis during the study. A number of significant differences were found between these patients and those with no thrombotic complications, most notably and increase in the von Willebrand factor antigen to ristocetin cofactor ratio and thrombin-antithrombin complex generation. These changes occurred before clinical detection of thrombosis. Thus, measurement of these parameters may be of predictive value in the diagnosis and monitoring of post-transplant thrombosis.     

Improved results of liver transplantation in patients with portal vein thrombosis

OBJECTIVE: To analyze the impact of preexisting portal vein thrombosis (PVT) on the operative management and outcome of liver transplantation. DESIGN: Retrospective review of 1423 patients who received transplants over 11 years. SETTING: Tertiary referral center. PATIENTS OR OTHER PARTICIPANTS: Seventy patients who underwent liver transplantation who had preexisting PVT. INTERVENTIONS: Portal vein thromboendovenectomy, vein grafting, or use of portal collateral veins for inflow during liver transplantation. MAIN OUTCOME MEASURES: Postoperative PVT, intraoperative transfusion, retransplantation rate, 30-day and 1-year actuarial survival rates. RESULTS: Operative management consisted of thromboendovenectomy in 61 cases, vein graft to the superior mesenteric vein in 6 cases, and vein graft to other mesenteric veins in 3 cases. The incidence of posttransplant PVT was 3% (n = 2). The mean +/- SD transfusion requirement was 23 +/- 18 U. The 1-year actuarial survival rate was 74% but improved from 66% in the first 35 cases to 82% in the latter 35 cases. CONCLUSIONS: Thromboendovenectomy is the procedure of choice for PVT. Results of liver transplantation in patients with PVT improve significantly with experience gained and are equivalent to results in patients without PVT.     

Low-dose aspirin therapy is associated with few side effects but does not prevent hepatic artery thrombosis in liver transplant recipients

Hepatic artery thrombosis occurs in 4% to 10% of adult patients and in up to 26% of children undergoing liver transplantation. Aspirin has been used to prevent this complication but may increase procedure-related and gastrointestinal bleeding. The aim of this study was to assess the efficacy and safety of low-dose aspirin in the prophylaxis of hepatic artery thrombosis. The histories of 529 patients who survived liver transplantation between September 1988 and December 1993 were reviewed retrospectively. The routine clinical practice followed until 1992 was to initiate oral aspirin therapy on the first postoperative day (81 mg daily in adults and 40 mg daily in children) as prophylaxis for vascular thrombosis. This was done in 354 patients. Aspirin was not administered to the remaining 175 patients. Hepatic artery thrombosis occurred in 13 patients treated with aspirin (3.7%) and in 7 patients not treated with aspirin (4.0%) (P = .85). Recipient age of younger than 2 years and low donor liver weight were the only factors that predisposed the patients to hepatic artery thrombosis. A total of 1,651 percutaneous liver biopsies were performed in this series, with 1,111 performed in patients treated with aspirin. Significant bleeding after liver biopsy occurred in 12 patients treated with aspirin (1.1%) and in 3 patients not treated with aspirin (0.6%) (P = .29). Gastrointestinal bleeding occurred in 66 patients treated with aspirin (18.9%) and in 23 patients not treated with aspirin (12.8%) (P = .08). Low-dose aspirin therapy is not shown to be effective in preventing hepatic artery thrombosis after liver transplantation. Although aspirin does not produce a statistically significant increase in the risk of bleeding after liver biopsy, there is a trend toward an increased incidence of gastrointestinal bleeding.     

Recurrence of alcoholic liver disease after liver transplantation

The acute toxicity of six metals [Hg, Cd, Cu, Zn, Cr(II), and Cr(VI)] to Daphnia magna neonates was evaluated using three different test media (Elendt M7, a complex medium containing EDTA; ASTM hard water and EEC, two simple media free of chelators). The EC50 values, at both 24 and 48 h, obtained for Zn, Cr(II), and Cr(VI) were similar in all of the media tested. Hg was more toxic in ASTM than in M7 and in EEC media. The toxicity of Cd and Cu was similar in ASTM and EEC media and higher when evaluated in M7 medium. Thus, M7 should be used only carefully for the toxicity evaluation of mixtures and effluents containing metals. It is recommended, however, that it be excluded from use in tests evaluating samples of unknown composition, or those known to contain Cu and Cd. For the metals tested in this study, a factor of five applied to each 48-h EC50 would be sufficient in order to attain the respective acute NOECs for immobility.     

Biphasic spiral computed tomography versus digital subtraction angiography for evaluation of arterial thrombosis after orthotopic liver transplantation

Aseptic loosening of implant components is a common and important complication of both cemented and uncemented prosthetic joint replacements. Wear particles derived from organic polymer and metal implant biomaterials are commonly found within macrophages and macrophage polykaryons in the fibrous membrane between loose implant components and the host bone undergoing resorption. In order to determine whether biomaterial particle-containing, foreign-body macrophages may contribute to periprosthetic bone resorption, we cultured murine monocytes that had phagocytosed particles of biomaterials commonly employed in bone implant surgery [polymethylmethacrylate (PMMA), ultra-high molecular weight polyethylene (PE), titanium and chromium-cobalt] on bone slices and glass coverslips with UMR 106 osteoblast-like stromal cells in the presence of 1,25-dihydroxy-vitamin D3. Under these conditions, all biomaterial particle-containing, foreign-body macrophages differentiated into osteoclastic cells, i.e. tartrate-resistant acid phosphatase (TRAP)-positive multinucleated cells capable of extensive lacunar bone resorption. This study shows that particle phagocytosis by macrophages does not abrogate the ability of these cells to undergo osteoclast differentiation. These findings emphasise the importance of the foreign-body macrophage response to biomaterial wear particles in the pathogenesis of aseptic loosening.