Centrilobular necrosis as a manifestation of venous outflow block in pediatric malnourished liver transplant recipients--case reports.

CLN is a frequent histological finding in biopsies after pediatric: LT, and its pathogenesis has not yet been fully clarified and has different causes. Among the vascular causes, VOB is sometimes difficult to diagnose, especially when technical variants such as split-liver, reduced-liver, or living-related LT are utilized. Three liver-transplanted malnourished children (ages 12, 20, and 28 months) developed altered LFTs and post-operative ascites with right pleural effusion (two cases) and jaundice (one case). Doppler ultrasound examinations were normal and liver biopsies showed CLN interpreted as severe ACR. There were no responses to the medical treatment. Additional investigation with CT angiography suggested obstructed hepatic vein drainage, which was confirmed by interventional radiology and angioplasty of the anastomosis between the hepatic vein and the inferior vena cava, with clinical and histological resolution. It is concluded that in malnourished children undergoing LT with technical variations, in which the occurrence of severe ACR is usually less common because of the severity of the patient condition, the finding of CLN should raise the possibility of VOB, so that excessive immunosuppression and its consequences can be avoided.

Aplasia medular após transplante hepático em pediatria / Aplastic anemia after pediatric liver transplantation

A aplasia de medula é uma das mais raras (<1 por cento) e sérias complicações após o transplante hepático por insuficiência hepática aguda grave viral não A, não B e não C. Esta condição clínica, que acomete simultaneamente o tecido hepático e o hematopoético, foi descrita pela primeira vez em 1987, por Stock, e a fisiopatologia relacionada é uma condição imunomediada, provavelmente secundária à infecção viral desconhecida, e associada a grave prognóstico. A recuperação espontânea da aplasia medular adquirida habitualmente é muito rara e 50 por cento-70 por cento dos pacientes respondem ao tratamento imunossupressor com ciclosporina A (CsA) e glubulina antitimocítica (ATG), mesmo após o transplante hepático. Além do tratamento imunossupressor, outra opção é o transplante de medula óssea (TMO). Apresentamos o caso de uma criança com aplasia medular grave após transplante hepático, por insuficiência hepática aguda grave, que recebeu tratamento imunossupressor com CsA e ATG e evoluiu com recuperação completa das três séries do hemograma.

Aplastic anemia (AA) is one of the rarest (<1 percent) and most serious complications of liver transplantation for fulminant non-A, non-B and non-C hepatitis. It was first described in 1987 by Stock; the mechanism involved is an immunologically mediated condition secondary to an unknown viral infection. The disease is associated with a dismal prognosis. Spontaneous recovery from acquired AA is very rare however some patients (50-70 percent) recover after immunosuppressive therapy, such as Cyclosporin A (CsA) and Antithymocyte globulin (ATG), even after liver transplantation. Another treatment option is bone marrow transplantation. We report on a child who developed AA following liver transplantation for fulminant viral hepatitis that was treated with intensive immunosuppression including CsA and ATG and achieved complete recovery.

Real-time and Doppler US after pediatric segmental liver transplantation : I. Portal vein stenosis.

BACKGROUND: Accurate diagnosis of portal vein (PV) stenosis by real-time and color Doppler US (CD-US) after segmental liver transplantation in children can decrease morbidity by avoiding unnecessary biopsy, PV hypertension, thrombosis and loss of the graft. OBJECTIVE: To evaluate CD-US parameters for the prediction of PV stenosis after segmental liver transplantation in children. MATERIALS AND METHODS: We retrospectively reviewed 61 CD-US examinations measuring the diameter at the PV anastomosis, velocities at the anastomosis (PV1) and in the segment proximal to the anastomosis (PV2), and the PV1/PV2 velocity ratio. The study group comprised patients with stenosis confirmed by angiography and the control group comprised patients with a good clinical outcome. RESULTS: PV stenosis was seen in 12 CD-US examinations. The mean PV diameter was smaller in the study group (2.6 mm versus 5.7 mm) and a PV diameter of <3.5 mm was highly predictive of stenosis (sensitivity 100%, specificity 91.8%). CONCLUSION: A PV diameter of <3.5 mm is a highly predictive CD-US parameter for the detection of hemodynamically significant stenosis on angiography.

Real-time and Doppler US after pediatric segmental liver transplantation : II. Hepatic vein stenosis.

BACKGROUND: Accurate diagnosis of hepatic vein (HV) stenosis by real-time and color Doppler US (CD-US) after segmental liver transplantation in children can decrease morbidity because it allows unnecessary biopsy, obstruction or thrombosis and loss of the graft to be avoided. OBJECTIVE: To evaluate CD-US parameters to predict HV stenosis after segmental liver transplantation in children. MATERIALS AND METHODS: Retrospective review of 79 CD-US examinations measuring velocity at the HV anastomosis (HV1) and the main trunk 1-2 cm proximal to the HV/IVC anastomosis (HV2), the HV1/HV2 ratio and the spectral waveform of HV2. The study group comprised patients with stenosis confirmed by angiography. The control group comprised patients with a good clinical outcome. RESULTS: HV stenosis was seen in 12 CD-US examinations. The mean HV1/HV2 ratio was higher in the study group (6.0 versus 4.0). An HV1/HV2 ratio of >4.1 was predictive of HV stenosis (sensitivity 83%, specificity 76%). CONCLUSION: An HV1/HV2 ratio of >4.1 is a highly predictive CD-US parameter for the detection of hemodynamically significant HV stenosis on angiography.

Mycophenolate mofetil promotes prolonged improvement of renal dysfunction after pediatric liver transplantation: experience of a single center.

Few studies have evaluated the long-term use of MMF in liver transplanted children with renal dysfunction. The aim of this study is to report the experience of a pediatric transplantation center on the efficacy and security of long-term use of a MMF immunosuppressant protocol with reduced doses of CNIs in stable liver transplanted children with renal dysfunction secondary to prolonged use of CsA or Tac. Between 1988 and 2003, 191 children underwent OLT and 11 patients developed renal dysfunction secondary to CNIs toxicity as evaluated by biochemical renal function parameters. The interval between liver transplantation and the introduction of the protocol varied from one to 12 yr. Renal function was evaluated by biochemical parameters in five phases: immediately prior to MMF administration; 3, 6, 12 and 24 months after the introduction of MMF. Among the patients, nine of them (82%) showed improvement of renal function parameters in comparison with the pretreatment values. The two patients that did not show any improvement were patients in whom the interval of time between OLT and the introduction of MMF was longer. All parameters of liver function remained unchanged. No episodes of acute or chronic rejection or increases in infection rates during the period were detected. Two patients developed transitory diarrhea and leukopenia that were reverted with reduction of MMF dosage. In conclusion, in liver transplanted pediatric patients with CNI-induced chronic renal dysfunction, the administration of MMF in addition to reduced doses of CNIs promotes long-term improvement in renal function parameters with no additional risks.